Due to a variety of factors, Apple’s iAds program hasn’t proven as successful as Apple was initially hoping for. Thanks to Apple’s penchant for control and expensive buy-in rates, which have subsequently been lowered, advertisers haven’t exactly been flocking towards Apple’s implementation of mobile ads.

The iAd business, introduced in 2010, has attempted to parlay Apple’s leadership in consumer electronics into mobile- advertising revenue — with mixed results. While the system has attracted ads from companies such as Walt Disney Co., some marketers have complained that iAd costs more than other ad services and only works on Apple devices. Apple trails Google Inc. (GOOG) in the mobile advertising market, which may generate $4.4 billion by 2015, according to research firm EMarketer Inc.

“Charging premium prices and reaching only Apple devices is a much harder sell,” said Noah Elkin, an analyst at EMarketer. “That has been a huge stumbling block.”

This past August, Apple’s iAds guru, Andy Miller, announced that he was leaving the company to start working for the Boston-based VC firm Highland Capital. While at Apple, Miller reported directly to Steve Jobs where the two would meet about once a week to discuss the latest developments in Apple’s foray into the advertising business.

Since Miller’s departure a few months back, Apple has actively been searching for a replacement and just recently found their guy – Todd Teresi.

Teresi comes to Apple from Adobe where he served as the company’s VP and GM of Media Solutions. Prior to that, Teresi held a number of managerial positions at Yahoo! and previously served as the CFO for Quantcast.

Without a doubt, Teresi will have his work cut out for him.

Meanwhile, Apple’s search for a replacement for the Senior VP of Retail position that became open when Ron Johnson left for the CEO position at JC Penney remains ongoing.